Dendritic Opal

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This opal variety is termed "dendritic" due to its internal collection of dendrites. Dendrites are fern-like inclusions of iron, manganese, or other metallic oxides that create bold patterns within the gem. Typically, dendritic opals are cut into slices to best exhibit nature's artwork. As you might guess, these pieces are one-of-a-kinds, as no two dendritic patterns are exactly the same. Usually these opals are white, yellow, blue, green or pink and show the black inclusions well.

Dendritic Opal Polished
Dendritic Opal Classification
Common Name Dendritic Opal
Species Opal
Dendritic Opal Optical Properties
Transparency Translucent - Opaque
Dispersion Strength: None
Refractive Index 1.370-1.520
Optic Character NA
Polariscope Reaction Singly Refractive (SR) With ADR, Aggregate (AGG)
Pleochroism None
Dendritic Opal Characteristic Physical Properties
Hardness 5-6.5
Streak White
Specific Gravity 1.980-2.500 Typical:2.150
Toughness Varies
Inclusions Dendritic opal has dendritic inclusions that look like moss or ferns. These inclusions are not plant fossils but are instead made of different metallic oxides, like manganese or iron.
Luster Vitreous, Resinous
Fracture Conchoidal, Uneven
Cleavage None
Dendritic Opal Chemistry & Crystallography
Chemical Name hydrated silicon dioxide
Chemical Formula SiO2-nH2O
Crystal System NA
Chemistry Classification Silicate

Dendritic Opal Colors

  • Multi-color Dendritic Opal Multi-color
  • White Dendritic Opal White
  • Bi-color Dendritic Opal Bi-color

Countries of Origin

United States of America (the); Unknown; Australia; Ethiopia

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Tim Matthews


Tim Matthews

Tim Matthews is President and Chief Executive Officer of Jewelry Television® (JTV), as well as a member of the company's Board of Directors. He oversees and leads all aspects of the company's powerful omni-digital retail platform that uniquely specializes in fine jewelry and gemstones. His passion for business and gemstones has led him to become a recognized expert in the field of gemology. He is a life member of the Gemmological Association of Great Britain (Gem-A) and has earned Gem-A's highest degrees, the Gemmology (FGA) and Diamond (DGA) diplomas. He is also a Graduate Gemologist (GG) of the Gemological Institute of America (GIA) and has also completed GIA's Graduate Diplomas in Diamonds, Colored Stones and Pearls. Under his leadership, JTV has become the leader in the sourcing and selling of color gemstones and jewelry.

This page was created on June 27, 2014.

This page was last edited on October 24, 2019.